Electronic counting ring



Dec. 12, 1950 R. E. MUMMA 2,533 739,

ELECTRONIC COUNTING RING Original Filed Dec. 27, 1943 Zhmcntor ROBERT E.MUMMA His Gttorneg Patented Dec. 12, 1950 ELECTRONIC COUNTING RINGRobert E. Mumma, Dayton, Ohio, assignor to The National Cash RegisterCompany, Dayton, Ohio, a corporation of Maryland Original applicationDecember 27, 1943, Serial Divided and this application July 18, 1947,Serial No. 761,813

25 Claims.

This invention relates to electron tube counting rings for countingelectric impulses, the rings being individually operable eitherforwardly or reversely for adding or subtracting operations.

The invention further provides means to join the rings into anaccumulator, so that transfer of carryover data may be accomplished atthe proper time according to whether an addition operation or asubtraction operation is being performed.

This is a division of my co-pending application for United StatesLetters Patent, Serial No. 515,718, which was filed December 27, 1943,and issued on June 1, 1948, as Patent No. 2,442,428.

The counter ring units which form the accumulator are an improvementover those shown in my co-pendingapplication for United States LettersPatent, Serial No. 396,505, which was filed June 4, 1941, and issued onJuly 30, 1946, as Patent No. 2,405,096. Each ring consists of a group ofgaseous discharge electron tubes, those tubes of a group being coupledin an endless counting chain for operation one at a time, in succession,by each of commonly received electric impulses. The improvement made inthe rings and the accumulator by this invention provides, means forentering data additively or subtractively therein, and to do suchwithout alfecting the accumulation of data up to the time of change fromadding to subtracting or vice versa. The direction of serial operationof the tubes in a denominational unit of the accumulator, formerlyfixed, is now by this invention controlled by means interconnecting thetubes, so that the chain may be operated as selected in a forward orreverse manner for a given entry, the direction of operation cle-vtermining whether the data is entered additively or subtractively.Denominational transfers of carryover data are made at the proper timein the operation of the counting ring, be the same in an addingoperation or in a subtracting operation.

Therefore, the principal object of the invention is to provideelectronic counting rings with circuits permitting forward or reverseoperation as selected.

Another object of the invention is to provide counting rings of electrontubes having denominational carryover transfer means between the ringsto form an accumulator, the ring to which the carryover is made beingoperated one step in either a forward manner or a reverse manner, asselected.

With these and incidental objects in view, the

invention includes. certain novel features of construction, circuits,and combinations of parts, .the essential elements of which are setforth in appended claims and a preferred form or embodiment of which ishereinafter described with reference to the drawing which accompaniesand I forms a part of this specification.

The drawing shows a denominational bank of an accumulator with theassociated denominational counting ring unit and the associateddenominational transfer unit. The gaseous triode electron tubes used inthe disclosed embodiment of the invention are of the thermionic cathodetype having an anode, a cathode, and a control grid and having aninternal potential drop during conduction of about 15 volts, with theelectrode elements so related that a tube will fire when the grid ismore positive than about 12 to 20 volts negative with respect to thecathode, depending on the anode-cathode potential. Circuits for heatingthe cathodes are indicated only conventionally. These tubecharacteristics are true of all the gaseous tubes shown in the drawing.

Values of potential, resistance, and capacitance, as given, are relativeand are given as one set of values which result in proper operation withthe specified tubes, but are not to be deemed the only circuit valuesthat can be used, as the principles involved in the invention permit ofdifferent levels for these relative values and of different relativevalues when electron tubes or other characteristics are used. Potentialsgiven are with respect to ground potential.

The accumulator counting ring unit shown in the drawing has tendigit-representing gaseous triode electron tubes for the digits 0, 1, 2,3,11- 4, 5, ,7! 7, H8, a d 9' A transfer tube T is provided for creatingan electric impulse to carry over a unit of data to the next higherdenominational order, which event occurs on the next impulse receivedafter the 9 digit tube is conducting in adding entries, or on the nextimpulse received after the 0 tube is conducting in subtracting entries.The counting ring may be described as of the parallel cathode extinctiontype, as all the digit tube cathodes, each of which is connected to apotential source through a resistance, are coupled electrostatical- 1yto a common extinguishing conductor, whereby, when a tube commences toconduct, the positive potential rise of its cathode is impressed on allthe other tubes of the ring, extinguishing the last conducting tube. Thetubes in the ring are rendered conducting one at a time in sequence inresponse to electric potential impulses-commonly impressedelectrostatically on the control grids of the digit tubes and thecontrol grid of the T tube. The conducting condition of a tube primesthe next tube in the ring to become conducting on the next commonlyreceived impulse, and the act of a tubes becoming conducting, because ofthe electrostatic coupling of each cathode in parallel to a commonconductor and the presence of a resistor in each cathode potentialsupply, causes the extinction of conduction in the previously conductingtube of the ring by forcing its cathode potential to a point morepositive than its anode potential. The direction of the in-, tertubepriming connections determines whether the ring operates in a forwardmanner or in a reverse manner, and the connection of the digit tubes tothe T tube determines on what impulse a carryover transfer is made.

An explanation of the structure and operation of one ring will give anunderstanding of the structure and operation of all the rings of I anaccumulator constructed of a plurality of these rings connected in aseries.

With reference to the drawing, the digit-representing tubes are numberedaccording to their digit value in the denomination. Each is a gaseoustriode of the type described as standard in the device. Anode potentialof 150 volts is applied at terminal H90, which is routed to the digittube anodes through resistor I200 of 10,000 ohms. Terminal H90 isconnected to ground through resistor I2I0 of 120,000 ohms and resistorI220 of 100,000 ohms in parallel with capacitor I200 of .01 microfarad.Point I230, which supplies anode potential for the T tube, is therebygiven a normal positive potential of about 68 volts. The cathodepotential of the T tube is derived from point I210, which is connectedto ground through resistor I250 in parallel with capacitor I260 ofmicro-microfarads, and connected to the negative 200-volt supplyconductor I200 through resistor I340 of 230,000 ohms. When said T tubebecomes conducting, due to the high current caused by the charging ofcapacitor I200 subsiding, there immediately ensues an oscillatoryphenomenon in the anode-cathode circuit due to the distributedinductance, which causes the cathode to rise in potential to a point,which results in a temporary cessation of anodecathode potential andextinguishment of conduction'in the tube.

Each of the digit tube cathodes obtains its potential from a point, likethe 8 tube cathode point I280, which is connected on one side to groundthrough a resistor, like resistor I290, of 25,000 ohms, and connected onthe other side to the negative 200-volt supply conductor 1300 through aresistor, like resistor I3I0, of 63,000 ohms, a point like point I320,and a resistor, like resistor I330, of 50,000 ohms. Each digit tube gridis given a normal controlling bias by being connected to a point in thecathode supply circuit of an adjacent tube, said cathode point beingthat of the adjacent tube of lower digit value in case the ring isadjusted for adding entries, and said cathode point being that of theadjacent tube of higher digit value in case the ring is adjusted forsubtracting entries. For instance, grid priming supply point I320 of the8 tube cathode is connected, in adding operations, through terminalI350, switch I360, and terminal I310, to prime the 9 tube grid throughresistor I380 of 100,000 ohms, point I390, and resistor I400 of 10,000ohms. When the switch key I430 is moved from add position to subtractposition, the 9 tube grid is primed by the 0 tube cathode priming supplyterminal I4I0, as switch I360 is moved to contact I035. During thetravel of a switch, such as switch I360, from one contact to another, itis supplied with sufficient negative potential through a contact, likecontact I03 I, connected to the negative supply conductor I300, tomaintain a controlling bias on the grid of the associated tube,preventing anomalous firing of the accumulator tubes.

' The transfer tube T grid is primed by potential applied to terminalI4'II, which in the adding position of key switch I430 obtains itspriming potential through'switch I480, in the position shown, andterminal M leading to the 9 tube cathode. In subtracting operations, theswitch I480 is moved to its other contact MEI, and thus terminal I4Ilreceives its prime from point I500, connected to prime supply point I433of the oathode of the 0 tube. The movement of key I430 from add positionto subtract position, in a similar manner, causes the cathode primingpoint of each tube in the bank to change contacts so as to prime thenextlower digit tube instead of the next higher digit tube. There is akey I430 for each bank of the accumulator.

Positive potential impulses impressed on the input terminal I000 areimpressed commonly on the grid of each of the digit tubes and thetransfer tube, each through an input capacitor such as capacitor IOI0 of.00005 microfarad. Each of the impulses will caus the primed tube toconduct and consequently will cause the digit tubes to become conductingone at a time in sequence in an endless chain manner.

As the T tube fires'and becomes conducting when the ring has exceededits capacity, an im pulse is taken from its cathode and by terminal I436is conveyed to the input conductor for the ring of next higherdenomination. Such next higher ring is not shown but, as has beenstated, is like the ring shown in the drawing.

Assuming the anode potential to be applied to the ring andassuming thatno tubes are conducting or a significant digit tube is conducting, aswitch like switch 438 may be closed temporarily to cause the 0 tube tobecome conducting by grounding its grid, registering zero and primingthe 1 tube to become conducting on receipt of the next input impulse incase the switch I430 is in adding positions or priming the 9 tube andthe "1" tube to become conducting on receipt of the next impulse in casethe switch I 430 is in subtracting position. The firing of the 0 tubewill extinguish any other significant digit tube which may be conductingwhen switch 438 is operated;

Thus, the ring may be operated either forwardly for adding orreverselyfor subtracting, the occurrence of the transfer unit beingprovided for at the proper count. As many rings may be connected in aseries as desired to form an accumulator of any desired size. Thetransfer carryover impulse will operate the next ring either forwardlyor reversel according to its adjustment. It is obvious that, in additionoperations, all rings connected in a series would be adjusted forforward operation and that, in subtraction operations, all ringsconnected in a series would be adjusted for reverse operation.

While the device shown and described herein is admirably adapted tofulfill the objects primarily stated, it is to be understood that it isnot intended to confine the invention to the one form or embodimentdisclosed herein, for it is susceptible 5. of embodiment in variousforms all coming within the scope of the claims which follow.

What is claimed is:

1. A plurality of units each including an electrode pair and aninter-electrode discharge con- .trol means; means to establish operativechain connections between the units, by connecting one of the electrodesof each pair to the control means of an adjacent unit of the chain; andswitching means operable to disestablish such connections and establishnew connections between said one electrode of each unit and the controlmeans of the adjacent unit of the former chain in a reverse direction.

2. A plurality of units each including an electrode pair and aninter-electrode discharge control means; means connecting the units inan operative endless chain by connecting one of the electrodes of eachpair to the control means of an adjacent unit of the chain; andadd-subtract control means to modify the connections between tubes todisestablish said connections and establish new connections between saidone electrode of each unit and the control means of the adjacent unit ofthe former chain, but in a reverse direction.

3. A plurality of digit-representing counting units each including anelectrode pair and an inter-electrode discharge control means; meansconnecting the units in an operative chain by connecting one of theelectrodes of each pair to the control means of one of the adjacentunits; and switching means operable to disestablish such connections andestablish new connections between said one electrode of each unit andthe control means of other adjacent unit of the former chain to form achain operative in a reverse direction.

4. A plurality of gaseous electron units each including an electrodepair and an inter-electrode discharge control means; and meansconnecting the units in an operative chain by connecting one of theelectrodes of each pair to the control means of an adjacent unit, saidmeans including switching devices operable to disestablish suchconnections and establish new connections between said one electrode ofone unit and the control means of an adjacent unit of the former chainbut in a reverse direction.

5. A plurality of electronic units each including an electrode pair;means to supply each pair with operating potential, said means includingcircuit elements to cause an electrode of each pair to change itspotential when conduction commences between the members of the pair;control means for each pair, which control means is normally suppliedwith potential suflicient to prevent conduction between the members ofthe associated pair; means connecting the potentialchanging electrode ofa pair to the control means of another adjacent unit to form an endlessoperative chain of the units, the condition of conduction in a unitcausing a potential change in the control means of the connected unit,and said connecting means including switching means operable todisestablish the above-mentioned electrode-control means connections andestablish similar electrode-control means connections between the unitsin a manner reverse in direction in the chain to said first-mentionedconnections; and means operable to supply a blocking bias potential tothe control means of the various pairs during the changing of theconnections to maintain the conducting status of the units during theestablishing and disestablishing of the connections.

6. A plurality of gaseous electronic units each including an electrodepair; means to supply each pair with operating potential, said meansincluding circuit elements to cause an electrode of each pair to changeits potential when conduction commences between the members of the pair;control means for each pair, which control means is normally suppliedwith potential sufficient to prevent conduction between the members ofthe associated pair; and means connecting the potential-changingelectrode of a pair to the control means of another adjacent unit toform an endless operative chain of the units, the condition ofconduction in a unit causing a potential change in the control means ofthe connected unit, and said connecting means including circuitchange-over devices operable to disestablish the electrode-control meansconnections and establishing similar electrode-control means connectionsbetween the units in a manner reverse in direction in the chain to saidfirst-mentioned connections.

'7. A plurality of electronic units each having at least an anode, acathode, and a control member; and means connecting the units in anendless operative chain wherein they may be rendered conducting one at atime in sequence in response to electric impulses impressed commonly onthe control members, said means including a connection from the cathodeof one unit to the control member of an adjacent unit in the chain, andsaid connecting means including circuit changing means operable todisestablish all such cathodecontrol member connections and establishsimilar connections from each cathode to the control member of thatadjacent unit of the chain situated in the opposite direction in thechain from said adjacent unit to whose control member the cathode wasfirst connected.

8. A plurality of gaseous electronic units each having at least ananode, a cathode, and a control member; means connecting the units in anendless operative chain wherein they may be rendered conducting one at atime in sequence in response to electric impulses impressed commonly onthe control members, said means including a connection from a cathode ofone unit to the control member of an adjacent unit in the chain, saidconnecting means also including switching means operable to disestablishall such cathode-control member connections and establish similarconnections from each cathode to the control member of that adjacentunit of the chain situated in the opposite direction in the chain fromsaid adjacent unit to whose control member the cathode was firstconnected; and means coupled to the units during the changing ofconnections to control the units to maintain non-conducting unitsagainst conduction while allowing the conducting unit to continue toconduct.

9. An electron tube counting ring including the combination ofconnections between adjacent tubes in the ring making it operable in onedirection around the ring; and switch means to change said connectionsto make the ring operable in the reverse direction said switch means tomaintain the operatin status of the tubes of the ring during saidchange.

10. An electron tube counting ring including the combination of aplurality of electron tubes arranged by connections between the tubes inan endless operating chain; means to impress electric signals on all thetubes, which tubes, by reason of said connections, are caused to becomeconducting around the chain in one direction one tube at a time insequence in response to said signals; and circuit change-over means forchanging the connections between tubes to cause the sequential operationof the tubes to occur in the opposite direction around the chain.

11. An electron tube counting ring including the combination of aplurality of gaseous electron tubes arranged by connections between thetubes in an endless operating chain; means to impress electric impulseson all the tubes, which tubes, by reason of said connections, are causedto become conducting step by step around the chain in one direction onetube at a time in sequence, there being one step of operation inresponse to each of said impulses; and switching means operable forchanging the connections to cause the sequential operation of the tubesto occur in the opposite direction around the chain said changing meansincluding means to maintain the operating status of the tubes of thering durin said change in connections.

12. An electronic impulse-counting device including the combination of adenominational set of electron tubes, there being a tube to representeach digit in the denomination including zero, and an extra tube fordenominational carryover counts; means connecting the digit tubes in anoperational ring wherein the digit tubes count electric impulsesimpressed commonly thereon by becoming conducting one at a time inendless succession, one digit tube responding to each impulse; meansconnecting the extra tube to the ring to be controlled thereby andoperated at a certain time in the cycle of operation of the ring; andadd-subtract control means operable to selectively control the directionof successive operation in the ring so as to accommodate additiveentries of data or subtractive entries of data and to change theconnection of the extra tube to the ring to cause the extra tube to beoperated at a different time in the cycle of operation of the ring insubtractive operations from its time of operation in additive operation.

13. An electronic impulse-counting device including the combination of adenominational set of gaseous electron tubes, there being a tube torepresent each digit in the denomination including zero, and an extratube for denominational carryover counts; means for connecting the digittubes in an operational ring wherein the digit tubes count electricimpulses impressed commonly thereon by becoming conducting one at a timein endless succession; means connecting the extra tube to the ring to becontrolled thereby and operated at a certain time in the cycle ofoperation of the ring and add-subtract control means for the connectingmeans to selectively control the direction of successive operation inthe ring so as to accommodate additive entries of data or subtractiveentries of data and forcontrolling the connection of the extra tube tothe ring to cause the extra tube to be operated at one time in the cycleof operation of the ring in additive entries and at another time in thecycle in subtractive entries.

14. In combination, a plurality of electron tubes each having at leastan anode, a cathode, and a control electrode; means to supplyanodecathode potential to the tubes, including a resistance in eachcathode supply circuit; means to supply normally controlling biaspotential to the control electrodes;.means to impress potential impulseson all the control electrodes, tending to cause them to lose control;means connecting the tubes in an endless operative chain by connectingthe cathode of a precedin tube to the control electrode of a succeedingtube, the combined eflect on a control electrode of the cathode rise inpotential of a preceding tube occurring at the same time as an impressedimpulse, causing the tube to become conducting; means to cause abeginning tube to become conducting; and switching means operable tochange the cathode-control electrode connections to cause the cathode ofa succeeding tube tobe connected to the control electrode of thepreceding tube in the chain so as to make the chain reversely operable.

15. In combination, a plurality of gaseous electron tubes each having atleast an anode, a cathode, and a control electrode; means to supplyanode-cathode potential to the tubes, including a resistance in eachcathode supply circuit; means to supply normally controlling biaspotential to the control electrodes; means to impress potential impulseson all the control electrodes, tending to cause them to lose control;means connecting the tubes in an endless operative chain by connectingthe cathode of a preceding tube to the control electrode of a succeedingtube, the combined efiect on a control electrode of the cathode rise inpotential of a preceding tube occurring at the same time as an impressedimpulse, causing the tube to become conducting; means to cause abeginning tubeto become conducting; switching means operable to changethe cathodecontrol electrode connections to cause the cathode of asucceeding tube to be connected to the control electrode of thepreceding tube inthe chain so as to make the chain reversely operable;and bias potential supply means operable to supply a blocking bias tothe tubes during an operation of the switching means to preventnonconducting tubes from becoming conducting.

16. An electronic counter of electric impulses, including a ring ofelectron tubes; connections between the tubes for causing theirsequential operation in endless chain one at a time in response toelectric impulses impressed commonly thereon; means to impress electricimpulses commonly on the tubes; and switching means operable forswitching the connections between the tubes to cause the sequentialoperation to proceed in a reverse direction said switching meansincluding means to maintain the operating status of the tubes of thering during the switching of said connections.

17. An electronic counter of electric impulses, including a ring ofgaseous electron tubes; connections between the tubes for causing theirsequential operation in endless chain in response to electric impulsesimpressed commonly thereon, one tube responding to each impulse; meansto impress electric impulses commonly on the tubes; and circuitchange-over means operable for switching the connections between thetubes to cause the sequential operation to proceed in a reversedirection.

18. A plurality of units each including an electrode pair and a controlmember; means connecting the units in an operative chain by connectingone of the electrodes of a preceding unit to the control member of asucceeding unit; an extra unit including an electrode pair and a controlmember; means connecting an electrode of a last unit of the chain to thecontrol member of the extra unit; and means operable to disestablish theelectrode-control member connections of the chain and to establishconnections between an electrode of a succeeding unit with the controlmember of the preceding unit and to disestablish the connection of theelectrode of the last unit of the chain with the extra unit controlmember and to establish a connection between an electrode of the firstunit of the chain and the control member of the extra unit.

19. A plurality of gaseous electronic units each including an electrodepair and a control mem ber; means connecting the units in an operativechain by connecting one of the electrodes of a preceding unit to thecontrol member of a succeeding unit; an extra gaseous electronic unitincluding an electrode pair and a control member; means connecting anelectrode of ,a last unit of the chain to the control member of theextra unit; and means operable to disestablish the electrode-controlmember connections of the chain and to establish connections between anelectrode of a succeeding unit with the control member of the precedingunit and to disestablish the connection of the electrode of the lastunit of the chain with the extra unit control member and to establish aconnection be tween an electrode of the first unit of the chain and thecontrol member of the extra unit.

20. An electronic electric impulse-counting device including thecombination of a denominational set of electron tubes, there being atube to represent each digit in the denomination including zero, and anextra tube for denominational carryover counts; means connecting thedigit tubes in an operational ring wherein the digit tubes countelectric impulses impressed commonly thereon by becoming conducting oneat a time in endless succession, one digit tube responding to eachimpulse; means operable to selectively control the direction ofsuccessive operation in the ring so as to accommodate additive entriesof data or subtractive entries of data; and means connecting the extratube to the ring so that it becomes conducting on the first impulsereceived by the ring after conduction occurs in the highest value digittube when the ring is selectively controlled for adding and becomesconducting on the first impulse received by the ring afterconductionoccursin the zero tube when the ring is selectively controlledfor subtraction.

21. An electronic electric impulse-counting device including thecombination of a denominational set of gaseous electron tubes, therebeing a tube to represent each digit in the denomination including zero,and an extra tube for de- 'nominational carryover counts; meansconnecting the digit tubes in an operational ring wherein the digittubes count electric impulses impressed commonly thereon by becomingconducting one at a time in endless succession, one digit tuberesponding to each impulse; means to selectively control the directionof successive operation in the ring so as to accommodate additiveentries of data or subtractive entries of data: and means connecting theextra tube to the ring so that it becomes conducting on the firstimpulse received by the ring after conduction in the highest value digittube when the ring is selectively controlled for adding, and becomesconducting on the first impulse received by the ring after conduction inthe zero tube when the ring is selectively controlled for subtraction.

22. An electronic electric impulse-counting device including thecombination of a plurality of 10 gaseous electron tubes each having atleast an anode, a cathode, and a control member, there being one tubefor each significant digit of a numerical denomination and for zero;means to supply sufiicient anode-cathode potential to support conductionin any tube, said means including a cathode resistor for each tube;means to supply biasing potential to all the control members normallysufficient to prevent conduction in the tubes; means connecting thedigit tubes including the zero tube in ascending order, cathode of alower value digit tube to the control member of a higher value digittube; the cathode of the highest significant digit tube being connectedto'the control member of the zero tube and the cathode of the zero tubebeing connected to the control member of the lowest significant digittube; an extra gaseous electron tube having at least an anode, acathode, and a control member; means supplying anode-cathode potentialto the extra tube including a cathode resistor; means supplying normallycontrolling bias potential to the extra tube; means connecting theoathode of the highest significant digit tube to the control member ofthe extra tube; means to imipress an electric input impulse on thecontrol members of all the tubes in the chain andon the control memberof the extra tube, any such impulse tending to cause, but falling shortof causing, all the tubes to become conducting; means to cause one ofthe chain tubes to become conducting, the consequent rise in its cathodepotential being 'sufiicient to make the tube to whose control member thecathode is connected responsive by becoming conducting on receipt of thenext commonly impressed input impulse; means to cause the act ofconduction occurring in a tube of the chain to extinguish any other thenconducting tube of the chain; means including circuit elements ofcapacitance and inductance cooperating with the anode-cathode supplycircuit of the extra tube to cause it to self-extinguish immediately itbecomes conducting, by reason of receipt of an impulse: at the same timethe highest significant digit tube .is conducting; and a switching meansto disestablish the cathode-control member connections between the tubesin the chain and between the extra tube of the chain and the chain andto re establish them so that in the chain a digit tube cathode will beconnected to the control member of the next lower value digit tube, andso that the cathode of the zero tube will be con nected to the controlmember of the highest significant digit tube and to the control memberof the extra tube, whereby the tubes in the chain may be operated in aforward direction or in a reverse direction as selected and to cause'theextra tube to become conducting on the impulse received after thehighest significant digit tube is conducting in the forward operation,and to cause the extra tube to become conducting on the impulse receivedafter the zero tube is conducting in the reverse operation.

23. An electronic electric impulse-counting device including theconibinaiion of a plurality of gaseous electron tubes each having atleast an anode, a cathode, an a control member, there being one tube foreach significant digit of a numerical denomination and for zero; meansto supply sufficient anode-cathode potential to support conduction inany tube, said means including a cathode resistor for each tube; meansto supply biasing potential to all the control members normallysufiicient to prevent conduction in 11 the tubes; means connecting thedigit tubes-including the zero tube in ascending order, cathode of alower value digit tube to the control member of a higher value digittube; the oathode of the highest significant digit tube being connectedto the control member of the zero tube and the cathode of the zero tubebeing connected to the control member of the lowest significant digittube; an extra gaseous electron tube having at least an anode, acathode, and a control member; means supplying anode-cathode potentialto the extra tube including a cathode resistor; means supplying normallycontrolling bias potential to the extra tube; means connecting thecathode of the highest significant digit tube to the control member ofthe extra tube; means to impress an electric input impulse on thecontrol members of all the tubes in the chain and on the control memberof the extra tube, any such impulse tending to cause, but falling shortof causing, all the tubes to become conducting; means to cause one ofthe chain tubes to become conducting, the consequent rise in its cathodepotential being sufficient to make the tube-to whose control member thecathode is connected ersponsive by becoming conducting on receipt of thenext commonly impressed input impulse; means to cause the act ofconduction occurring in a tube of the chain to extinguish any other thenconducting tube of the chain; means including circuit elements ofcapacitance and inductance cooperating with the anode-cathode supplycircuit of the extra tube to cause it to selfextinguish immediately itbecomes conducting, by reason of receipt of an impulse at the sametinieth highest significant digit tube is conducting; a switching meansto disestablish the oathode-control member connections between the tubesin the chain and between the extra tube of the chain and the chain andto reestablish them so that in the chain a digit tube cathode will beconnected to the control member of the next lower value digit tube, andso that the cathode of the zero tube will be connected to the controlmember of the highest significant digit tube and to the control memberof the extra tube, whereby the tubes in the chain may be operated in'aforward direction or in a reverse direction as selected and to cause theextra tube to become conducting on the impulse received after thehighest 'and a second chain of tubes similar to the first chain oftubes, having its input impulse means connected to the cathode of theextra tube of the first chain.

24. An electronic electric impulse-counting deincludin-g groups ofelectronic units, each group representing a denominational order of anumerical system and there being in each order group a unit for eachdigit including zero; an extra unit for each group for transferringdenominational carryovers, said unit, when responsive, creating anelectric impulse; input means for each group of units and the associatedtransfer unit for commonly impressing thereon electric impulses to becounted; selective circuits for each group of units and its associatedtransfer unit for rendering the group units responsive to input impulsesstep by step one at a time in sequence in an endless operative chain inascending or descending digit value order as selected, said selectivemeans connecting the extra unit so as to be responsive on an impulsemaking the zero unit responsive in the' ascending order operation, andto be responsive on an impulse makingthe lowest significant digit unitresponsive in the descending order operation; and means connecting theextra unit of a group with the input means of the next higherdenominational group so that, when said extra unit is responsive, ittransmits an impulse to the said'next higher denominational group onestep.

25. An electronic numerical accumulator in cluding a plurality ofelectron tube denominational rings each responsive to denominationalinput electric impulses by step-by-step endless chain response of thetubes in a ring, one tube being responsive to each impulse anddenominational carryover transfer means for each of the chain, saidtransfer means producing an impulse for each complete cycle of operationof the chain; means connecting the transfer means of a lower order tothe ring of next highe order that said next higher order ring may begiven a step of operation for each complete cycle of the lower ring; anda switching means in each ring for determining the direction ofoperation of the tubes in the endless chain in the ring, said switchingmeans also selecting the time of operation of the associated transfermeans in a cycle.

' ROBERT E. MUMMA.

REFERENCES CITED The following references are of record in the file ofthis patent:

Certificate of Correction Patent No. 2,533,739 December 12, 1950 ROBERTE. MUMMA It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 6, line 69, after the Word means insert including means; column11, line 26, for ersponsive read responsv'we; column 12, line 1, for thesyllable and hyphen deread device;

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the case in the PatentOflice. Signed and sealed this 13th day of February, A. D. 1951.

[sun] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

